90 SFOLIA ZEYLANICA. 



back to a period long before the clearing of our forests commenced. 

 Possibly the scheme of coloration was unconsciously modelled upon 

 the form taken by some of the shapeless white fungi that grow upon 

 decaying wood. 



{Fig. 6.) There is a common long-horned grasshopper with 

 mottled brownish wings, which clings close against the branches of 

 the trees upon the leaves of which it feeds. Its wings partially 

 encircle the branch , and its back is rugged like the bark. When at 

 rest in this position it looks merely like some natural excrescence of 

 the branch itself. 



{Fig. 7.) And a small Homopterous insect {Atracis neitneri) 

 is so like — in texture and colourmg — to a patch of gray-green 

 lichen that it is indistinguishable until it is disturbed and flies off. 



Another common form of protective resemblance, in which the 

 insect imitates a small lump of earth, has been adopted by many 

 members of the beetle tribe. Such species are of a dull brown 

 colour, and have a rough granular or warty surface. They do not 

 necessarily live in the soil, but have acquired the habit — when 

 alarmed — of suddenly dropping from their perch and falling to the 

 ground, where they lie perfectly motionless, with limbs close pressed 

 to the body, until the danger has passed. The habit of feigning 

 death is itself a form of protective mimicry. 



As a general rule, predatory animals will not touch even their 

 natural prey when it is dead or motionless. A preying mantis, one 

 of the most voracious of insects, will take no notice of a motionless 

 insect, but will seize it as soon as it shows any signs of life. Many 

 defenceless insects, therefore, have acquired the habit of lying inert 

 and to all appearances dead when alarmed. 



Insects that inhabit grass land have very generally assumed an 

 elongate narrow shape that assimilates itself to the form of the 

 stems and blades of the grasses amongst which they conceal 

 themselves. Examples of many different families may be found 

 exhibiting this device. We find in the patanas long narrow grass- 

 hoppers, stick insects, mantises, bugs, caterpillars, and even moths 

 of the same general form. 



The caterpillar of a small green moth {Thalassodes, sp.) disguises 

 itself by fastening pieces of leaves and withered blossoms to the 

 fleshy spines on its back. 



The phenomenon of protective mimicry proper is closely involved 

 with that of warning colours, in which an insect has assumed con- 

 spicuous colours or markings that are recognized by insectivorous 

 birds and other animals as associated with something dangerous or 

 distasteful. In contradistinction to 'protective resemblance, which 

 results in rendering the object inconspicuous, 'protective mimicry 

 usually tends in the direction of conspicuousness. The wasp tribe 

 are usually brightly banded with orange and black, and any bird 



